Cook noodles according to package and set aside
Cut spare ribs between bones and add to a pot of cold, salted water. Bring to a boil and boil for 2 minutes
Drain and rinse ribs and add back into pot with 6 clean cups of water. Add dried shrimp and simmer for 30 minutes
Take shrimp out and add bouillon to the remaining broth and ribs
Add dried shrimp and shallot to a food processor and blend until shrimp is finely shredded
Mix shrimp/shallot mixture, crab, pork, minced prawn, egg, salt and pepper together
Add tomatoes and tofu to broth and bring to a boil
Reduce the heat and carefully spoon rieu mixture into the broth.
Bring broth back to a simmer for about 15 minutes until rieu is cooked.
Serve over vermicelli noodles with chopped scallion and cilantro